The Okavango River Basin –Challenges &
Opportunities.
OKACOM, 2003, Corvallis
Several slides compiled by Dr Peter Ashton – CSIR (2002)
MAKGADIKGADI CATCHMENT
Map sourced
from GEF Report on Okavango
Delta Study
100 km
N
ZAMBIA
Boteti River basin
ZIMBABWE
NAMIBIA
ANGOLA
BOTSWANA R.S.A.
Deception Pan basin
Ntwetwe Pan basin
Sowa Pan basin
Okavango Basin
Lake Ngami
Okwa R.
Nata R.
Omatako R.
Cubango R.
Okavango Delta
Cuito R.
Kavango R.
Cuando R.
Chobe R.
Zambezi R.
RAINFALL DISTRIBUTION
300400500600700800900
10001100120013001400
M.A.P. (mm)
ZAMBIA
NAMIBIA
BOTSWANA
ZIMBABWE
ANGOLA
L. Ngami
L. Xau MakgadikgadiPans
Maun
Savuti R.Rundu
Kavango R.
Cuito R.Cubango R.
Nata R.Boteti R.
Zambezi R.
Zambezi R.
Cuando R.
Omatako R.
Chobe R.
OKAVANGODELTA
20° E
15° S
20° S
VARIABLE ANNUAL INFLOWS AT MOHEMBO (1933 - 2001)
Per
cen
tag
e o
f m
ean
an
nu
al i
nfl
ow
40
60
80
100
120
140
160
180
1930 1940 1950 1960 1970 1980 1990 2000
Time (Years)
5-yearMovingaverage
Max.: 16,145 x 106 m3
Mean: 9,863 x 106 m3
Min.: 5,321 x 106 m3
TIMING OF DELTA RAINFALL INFLOW AND OUTFLOW
0
50
100
1000
500
0
40
20
0J J A S O N D J F M A M J J A S O N D J F M
Rai
nfa
ll (m
m)
Infl
ow
(10
6 m
3 )O
utf
low
(10
6 m
3 ) Outflow Volume(Thamalakane)
Inflow Volume(Mohembo)
Rainfall(Average of Shakawe
plus Maun)
DELTA WATER BALANCERIVER INFLOWS
+ 76 %
OUTFLOW- 3 %
DIRECTEVAPOTRANSPIRATION
- 84 %
DIRECTRAINFALL
+ 24 %
RIPARIAN SOILS &GROUNDWATER
- 13 %
PROJECTED WATER NEEDS IN OKAVANGO BASIN
0
2040
6080
100120
140
Angola Botswana Namibia
Wat
er v
olu
me
(mil
lio
n c
ub
ic
met
res/
year
)
2000 2020
Anticipated total water requirement = 300 million m3 / year in 2020
RATIFIED INTERNATIONAL CONVENTIONS
CountryTreaty / Protocol Ratification Date
Ramsar UNCBD UNCCD UNCSW UNFCCC
Angola N/P 01/04/98 30/06/97 N/P 17/05/00
Botswana 09/12/96 12/10/95 11/09/96 N/P 27/01/94
Namibia 23/08/95 16/05/97 16/05/97 N/P 19/05/95
N/P = Not yet party to Treaty / Protocol
RAMSAR SITE LOCATION
ZAMBIA
NAMIBIA
BOTSWANA
ZIMBABWE
ANGOLA
L. NgamiL. Xau Makgadikgadi
Pans
Maun
Savuti R.Rundu
Kavango R.
Cuito R.Cubango R.
Nata R.
Boteti R.
Zambezi R.
Zambezi R.
Cuando R.
Omatako R.
Chobe R.
OKAVANGODELTA
20° E15° E
15° S
20° S
Boundary of the Okavango Delta RAMSAR site
MOSAIC OF HABITATS
The Okavango Delta has an enormous variety of
different habitat types and a diverse array of aquatic
and terrestrial species